nice preamp with ne 5534 or 5532

[Andui]

hello,
i`m building my own amp but run into a problem with the preamp.
i can't find a good schedule.... :cry:
i wan't an preamp who sounds very simular to that from my friend's marshall amp (it's an 100 watt transitor don't know it's type)
i also want it to have two inputs 1 for distortion and 1 for clean so i can change the volume of both (will be switched by an relais)
and i also want it to have an bass mid an treble tone control
has any one some schematic's for this?
and the power supply should be about 9v dc if it's possible

[RDV]

A suggestion:


RDV

[RDV]

Sound samples here.
http://www.runoffgroove.com/salvo.html

RDV

[Andui]

thank's for the reply rdv but for that one i have to get a lot of parts wich i don't have and the nearest shop is 40 km. and i already have a distortion channel but i`m missing the preamp and tone control ...

[RDV]

]

RDV

[Andui]

 i have build that preamp but it doesn't work i used an ne 5534 but i don't get any sound on the output.
i have measured with my ossiloscoop and i found out that the signal goes until the non inverting input and there it just dissapears. i have tried several new ne 5534's but none seemed to work has annybody an idea ?

edit :
instead of a normal i uF cap i used an elco does that matter ?

[petemoore]

Polarixed caps may have polarity issues...you have to have the - side of the cap connected to the low voltage potential side'...
 I'm blindly saying that schematic has to work, because I don't RDV would suggest it or display it if it didn't. It looks like a simpple OA stage followed by a little TC action, I can't see why it wouldn't work.
 Did you take some IC pin voltages for diagnosis?

[Andui]

well i have changed the elco but is doesn't make any difference all everything before the op amp works and after but the opamp just bloks all the sound between pen 4 and 7 i measure 8.75 volt. but i have tried several new op amps and none works  

[Eric H]

well i have changed the elco but is doesn't make any difference all everything before the op amp works and after but the opamp just bloks all the sound between pen 4 and 7 i measure 8.75 volt. but i have tried several new op amps and none works  

You should have around 4.5 volts at pin 2,3 and 6.

You clearly have a wiring error, or (less likely) a bad component.

-Eric

[toneman]

check all the pinouts!!
using quad in place of dual??
Vr should B @ 4.5VDC, or 1/2 supply V
as mentioned previously.
Have U got pot wired correctly?
Try taking pot out of circuit and substitue with
fixed resistor, say 20K.  
Should give gain greater than one.
Maybe even remove tone controls,
and just concentrate on the opamp.
Got pwr 2 correct pins""
again, check pinout.
tone

[RDV]

//www.ben.cz/download/120490/ne5534.pdf

I updated the schem with polarity.
Be sure of pinout.

RDV

[toneman]

on an "uncompensated" opamp,
U need to tie up the comp/balance pins.
on the NE5534, an 8pin DIP,
pin 1-balance
pin-8-balance/compensation
pin-6-compensation

see the LM748 for balance/compensation hookup..
here's a link to the LM748 page

http://www.national.com/pf/LM/LM748.html

pinout looks identical to NE5534.
page 3 has inverting amp with balance&compensation.
seem like all single opamp packages have all those
"extra" pins......

staytuned
tone

[Andui]

thanks for the help  
it's working now so  
the problem was that the trace for ground on my pcb was cut trough by me by accident  :roll:
now i only have to fix the distortion (very weak sound) but that will work out fine

[Andui]

@rdv

could you post the schematic once again ?
i've lost it and it's offline.

thanks.

[RDV]

I hope that's the one you were looking for.

RDV